Autonomous vehicles and vehicles with advanced driver assistance systems (“ADAS”) may employ a plurality of visual sensors providing a controller or controllers with situational-awareness data including image data indicative of traffic, proximity to other vehicles, traffic control signals, traffic lane locations, etc. Example visual sensors include cameras and LIDAR sensors. Such visual sensors need to be kept clean to allow the vehicle to continue operating. Fluid washers may be used to clean the sensors. However, such systems are only effective when they have an available supply of washer fluid.